Elastic tape guides and tensioning means for sewing machines



p 1956 J. .1. DOLNEY 2,761,401

ELASTIC TAPE GUIDES AND TENSIONING MEANS FOR SEWING MACHINES Fil ed Nov. 13, 195s 2 Sheets-Sheet 1 IN V EN TOR. Joseph J. Doiney WITNESS BY ATTORNEY J. J. DOLNEY Sept. 4, 1956 ELASTIC TAPE GUIDES AND TENSIONING MEANS FOR SEWING MACHINES Filed NOV. 13, 1953 2 Sheet-Sheet 2 INVENTOR. Joseph J. Do/ney ATTORNEY WITNESS United States Patent ELASTIC TAPE GUIDES AND TEN SIONIN G MEANS FOR SEWING MACHINES Joseph J. Dolney, Sn'atford, 'Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation of New Jersey Application November 13, 1953, Serial No. 391,940

Claims. (Cl. 112-152) The present invention relates to sewing machines and has for a primary object to provide an improved elastic tape guide and tensioning means therefor.

More particularly it is an object of the present invention to provide a combined guide and tensioning means for elastic tape that is adapted to be positioned closely adjacent the stitching mechanism of a sewing machine. It is a further object of this invention to provide such a guide and tensioning means that is economical, durable, and thoroughly dependable in use.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a fragmentary perspective View of a sewing machine to which there has been applied a combined guide and tensioning means constructed in accordance with the present invention, with certain of the underlying elements of the machine which form no part of this invention omitted for the sake of clarity, and the workfolder in thrown-out position to show more clearly the tape guide and tensioning means.

Fig. 2 is a fragmentary front elevation view of the machine illustrated in Fig. 1, but with the work-folder in operative position.

Fig. 3 is a fragmentary vertical section view taken substantially on the line 33 of Fig. 2.

Fig. 4 is a fragmentary portion of a piece of work after the stitching operation by a machine as disclosed herein has been performed on the same.

The present invention is not limited to use with any particular sewing machine and it is for purposes of illustration only that it is herein disclosed as associated with a machine of the two-needle, chain-stitch, compound feed type such as illustrated in the U. S. patent of Zeier, No. 2,329,681, September 14, 1943, and the patents referred to therein. Since the specific machine constitutes no portion of the present invention, it is illustrated only insofar as is necessary to describe properly the improved guide and tensioning means. Reference may be had to the above patent for a more complete description of the machine.

As illustrated in the drawings, there is provided a sewing machine having a bed 1 from the one end of which rises a standard 2. In the usual manner the standard 2 supports a bracket-arm (not shown) that terminates in a head 3 in which there is slidably mounted for vertical reciprocation and transverse swinging a needlebar 4 carrying at its lower end a needle-clamp 5 holding a pair of spaced needles 6. Also mounted in the head 3 is a resser-bar 7 having a presser-foot 8 secured to the lower end thereof, which resser-foot includes a shank 9, a sole-plate 10 pivotally mounted thereon by a pivotpin 11, and a spring 12 for biasing the 'heel of the soleplate 10 downwardly. In the customary manner, the resser-foot 8 is designed to be resiliently urged downwardly by a relatively heavy spring (not shown) into engagement with a throat-plate 13 that is carried by a cover-plate 14 which is one of two bed cover-plates 14 and 15 secured to the bed 1 by screws 16 and 17, respectively, which cover-plates form the work-supporting surface of the machine. Directly beneath the presserfoot 8, the throat-plate 13 is provided with the usual feed-dog slots 18 through which feed-dogs 19 project into engagement with the work. The feed-dogs 19 are carried by a feed-bar 20 to which is imparted a fourmotion feeding cycle to effect feeding of the work past the stitching mechanism. Appropriate slots 21 and 22, see Fig. 3, are also formed in the sole-plate 10 of the resser-foot and in the feed-dogs 19 to permit workpenetrating strokes of the needle, which slots are elongated in the direction of feed to accommodate the work feeding motions of the needle. The bed mechanism of the machine also includes a pair of threaded loopers one of which appears at 23, in Fig. 3, that are adapted to cooperate individually with the needles 6 in the formation of two-thread chain stitches, and a pair of loop-spreaders, one of which appears at 24. The bed cover-plate 14 is provided with a rectangular cut-away portion 25 at the front of the same that extends from the front edge to the throat-plate 13, the edges of which cut-away portion are reduced to form a flange 26. The cut-away portion 25 provides for accommodation of a combined tape guide and tensioning means 27 and a work-folder 28 as hereinafter disclosed.

The combined elastic tape guide and tensioning means 27 is carried by a radius-arm 29 pivotally secured at one end to the bed cover-plate 15 by a pivot-screw 30. At its opposite end, the radius-arm 29 is bent downwardly at substantially a right angle immediately adjacent the edge of the cut-away portion 25 as defined by the flange 26 to provide a leg 31. A guide-supporting plate 32 ineluding a leg 33 formed at substantially a right angle thereto, is secured to the leg 31 of radius-arm 29 by screws 34 passing through the leg 33 and screwed into the leg 31. The plate 32 is arranged at a substantial inclination forwardly and downwardly with respect to the radius-arm 29 and consequently to the bed cover-plate 14 so that it lies wholly beneath the work-supporting surface of the bed and thus provides adequate space for the work-folder 28. The radius-arm 29 is firmly maintained in operative position against vertical movement by means of a finger 35, see Fig. 2, which may be formed by bending upwardly into a horizontal position a strip formed by vertically slitting the leg 31, which finger underlies the flange 26 whereas the radius-arm 29 generally overlies the same. The radius-arm is held in operative position against pivotal movement about the pivot screw 30 by a spring clip 36 that includes a leg 37 screwed to a suitable portion of the bed 1.

The elastic tape guide and tensioning means 27 comprises an elongated U-shaped member 38 having a bottom wall or tape-supporting surface 39 and opposed upstanding tape-guiding sidewalls 40. The U-shaped member 38 is secured to the plate 32 by a pair of brackets 41, each having a first leg that is fastened to the outer surface of one of the side-walls 40 as by welding and a second leg that is secured to the plate 32 by a screw 42 extending through a transversely elongated slot 43 in the bracket, whereby the guide 27 may be adjustably secured to the plate for limited lateral movement relative to the stitching mechanism. Toward the delivery end of the guide 27, there is provided a bridge-piece 44 arranged transversely of the same and spanning the distance between the upper edges of the side-walls 40 in spaced longitudinally-inclined relationship with the tape-supporting surface 39. The bridge-piece 44 is secured in the desired position by means of integral depending legs 45 that are fastened to the outer surface of the side-walls 40 as by soldering, welding or the like. A second bridge-piece 46 is secured in a similar manner to the opposite end of the guide, i. e., by integral depending legs 47 secured to the outer surfaces of the sidewalls 40.

Mounted within the U-shaped member 38 is a slide 48 having a tape-engaging plate 49, upstanding side-walls 50 and an upstanding end-wall 51. The plate 49 is arranged parallel and opposed to the tape-supporting surface 39 of the member 38 for relative sliding longitudinally thereof. Fixed to the upper face of the plate 49 as by soldering is a cam 52 arranged longitudinally of the U-shaped member 38. The cam 52 is formed of sheet metal and is substantially like a wedge that varies in height in a direction normal to the plate 49 along a smooth line from a minimum that is located adjacent the discharge end of the guide. The maximum height of the cam 52 is greater than the distance between the underface of the bridge-piece 44 and the upper-face of the plate 49 when the under or tape-engaging face of the plate is resting on the tape-supporting face 39 of the member 38, whereas the minimum height is less than the distance between the two when the tape-engaging surface and the tape-supporting surface are separated by a tape of a maximum thickness designed to be accommodated. It should also be noted that the cam 52 is arcuate in cross section and that the bridge-piece 44 is inclined longitudinally of the guide, see Fig. 3, at substantially the same inclination as that of the cam 52, thus obtaining a line contact between the two which would permit transverse self-aligning of the plate 49 relative to the tapesupporting surface to maintain a parallel relationship between the two.

To provide for longitudinal adjustment of the slide 48 there is a rod 53 having one end secured to the endwall 51 of the slide 48 by opposed lock-nuts 54 screwed upon the threaded end thereof upon opposite sides of the end-wall 51, see Fig. 3. The opposite end of the rod 53 extends through a vertically elongated slot 55 formed in an angle bracket 56 secured to the bridge-piece 46 by screws 57, and has screwed upon the threaded end thereof a lock-nut 58 and an adjusting nut 59. A spring 60 encircles the rod 53 and abuts at one end against the inner one of the nuts 54 and at the opposite end against a Washer 61 that in turn abuts against the bracket 56. From the above, it will be understood that the spring 6!) acts to bias the slide 48 longitudinally of the member 38 toward the delivery end thereof, the action of the spring being limited by the adjustment of the nut 59 relative to the rod 53. Adjustment of the slide 48 longitudinally of the guide will act through the cam 52 and the cooperating bridge-piece 44 to vary the spacing between the tape-supporting surface 39 and the bottom surface of the tape-engaging plate 49, which spacing defines the slot through which the elastic tape is run, and variations of the slot will vary the tension thereby imposed upon the tape passing through. The elongated slot 55 permits the plate 49 to remain parallel to the tape-supporting surface 39 longitudinally thereof despite longitudinal adjustments of the slide 48. Thus, the slot 55 together with the use of a line contact between the cam 52 and the bridge-piece 44 permits compensating adjustments to hold the plate 49 parallel to the tapesupporting surface 39.

The present elastic tape guide and tensioning means is for use in manufacturing products such as illustrated in Fig. 4, which comprises a piece of work W having an under folded edge E, and an elastic tape T stitched to the same while in a stretched condition by two parallel lines of stitches S arranged along the edge of the tape, the tape being positioned along the under folded edge of the work and concealing the same. Since the elastic tape is stitched to the work while in a stretched condition, it contracts after passing through the machine and thus produces a ruffling effect as illustrated in Pig. 4. The work W is guided and the edge thereof is underfolded by the work-folder 28 which is of conventional and wellknown construction and so will not be further described herein. The work-folder 28 is secured to a radius-arm 62 by screws 63 extending through elongated holes 64 in the same and being screwed into the radius-arm. The radius-arm 62 is pivoted to the bed 1 together with arm 29 by the pivot-screw 30. A spring 65 is interposed between the head of the screw 30 and the radius-arms 29 and 62 to urge the same against the bed. The workfolder 28 is held in operative position by means of a plate 66 secured to the radius-arm 62 by screws 67, which plate is designed to seat upon the flange 26 of the cover-plate 14.

As set forth above, the elastic tape is run through the guide 28 between the side-walls 40 which serve to guide the same and between the tape-supporting surface 39 and the tape-engaging surface of the slide-plate 49 which serve to impose an adjustable tension upon the same. It has been found that when an elastic tape tensioning means is located at a distance from the stitching point, there is a tendency for the tape guide to unthread itself when the tape is cut at the end of each stitching operation. In the present combined elastic tape guide and tensioning means, this tendency has been overcome by placing of the tensioning means near the discharge end of the guide, and by the fact that the present guide has been so constructed that it can be positioned with the discharge end immediately in front of the stitching point.

Having thus set forth the nature of the invention, what I claim herein is:

l. A combined elastic tape guide and tensioning means for sewing machines comprising an elongated U-shaped member having a tape-supporting surface and opposed upstanding tape-guiding side-walls, a bridge-piece fixed relative to said side-walls and arranged transversely of said U-shaped member in spaced relationship with said tape-supporting surface, a slide having a tape-engaging plate disposed substantially in parallel relationship with the tape-supporting surface of said U-shaped member and disposed between said bridge-piece and said tapesupporting surface, a wedge-shaped cam carried by said slide and inclined normal to said slide, said cam being arranged in cooperative relation with said bridge-piece for displacing said slide in a directon normal to said tape-supporting surface upon movement of said slide longitudinally relative to said tape-supporting surface to control the maximum spacing between said tape-supporting surface and said tape-engaging plate, and means for moving said cam longitudinally of said tape-supporting surface and relative to said bridge-piece to maintain said tape-engaging plate in any one of a plurality of adjusted positions normal to said tape-supporting surface.

2. A combined elastic tape guide and tensioning means for sewing machines comprising an elongated U-shaped member having a tape-supporting surface and opposed upstanding tape-guiding side-walls, a bridge-piece fixed relative to said side-Walls and arranged transversely of said U-shaped member in spaced relationship with said tape-supporting surface, a slide having a tape-engaging plate disposed substantially in parallel relationship with the tape-supporting surface of said U-shaped member and disposed between said bridge-piece and said tapesupporting surface, a wedge-shaped cam of arcuate crosssection carried by said slide and arranged in cooperative relation with said bridge-piece for displacing said slide in a direction normal to said tape-supporting surface upon movement of said slide longitudinally relative to said tape-supporting surface to-control the maximum spacing between said tape-supporting surface and said tape-ere gaging plate, and means for moving said slide to any one of a plurality of adjusted positions longitudinally of said tape-supporting surface and relative to said bridgepiece to maintain said tape-engaging plate in any one of a plurality of adjusted positions normal to said tape-supporting surface.

3. A combined elastic tape guide and tensioning means for sewing machines comprising an elongated U-shaped member having a tape-supporting surface and opposed upstanding tape-guiding side-Walls, a bridge-piece carried by said side walls and disposed across the top thereof transversely of said U-shaped member in spaced longitudinally inclined relationship with said tape-supporting surface, a slide having a tape-engaging plate disposed substantially in parallel relationship with the tape-supporting surface of said U-shaped member and disposed between said bridge-piece and said tape-supporting surface, a Wedgeshaped cam carried by said slide and arranged in cooperative relation with said bridge-piece to control the maximum spacing between said tape-supporting surface and said tape-engaging plate, said cam being arcuate in cross-section and being longitudinally inclined with re spect to the tape-supporting surface at substantially the same angle as the angle of inclination of said bridgepiece, and means for maintaining said slide in adjusted position longitudinally of said tape-supporting surface.

4. A combined elastic tape guide and tensioning means for sewing machines comprising an elongated U-shaped member having a tape-supporting surface and opposed upstanding tape-guiding side-walls, a bridge-piece carried by said side-walls and disposed across the top thereof transversely of said U-shaped member in spaced longitudinally-inclined relationship with said tape-supporting surface, a slide having a tape-engaging plate disposed substantially in parallel relationship with the tape-supporting surface of said U-shaped member and disposed between said bridge-piece and said tape-supporting surface, a Wedge-shaped cam carried by said slide and arranged 1n cooperative relation with said bridge-piece to control the maximum spacing between said tape-supporting surface and said tape-engaging plate, said cam being arcuate in cross-section and being longitudinally inclined with respect to the tape-supporting surface at substantially the same angle as the angle of inclination of said bridgepiece, and means for maintaining said slide in adjusted position longitudinally of said tape-supporting surface, said means comprising a bracket fixed with respect to said U-shaped member and having an elongated aperture therein, a rod fixed at one end to said slide and at the other end extending loosely through said aperture, a coil spring encircling said rod and abutting at one end against the slide and at the other end against the bracket, and an adjusting nut screwed onto the threaded end of said rod upon the opposite side of said bracket from said spring.

5. Elastic tape tensioning means for sewing machines comprising a tape-supporting surface, a bridge-piece fixed relative to and in spaced relation with said tape-supporting surface, a slide having a tape-engaging plate disposed substantially in parallel relationship with said tape-supporting surface and disposed between said bridge-piece and said tape-supporting surface, a wedge-shaped cam carried by said slide and inclined normal to said slide, said cam being arranged in cooperative relation with said bridge-piece for displacing said slide in a direction normal to said tape-supporting surface upon movement of said slide longitudinally relative to said tape-supporting surface to control the maximum spacing between said tape-supporting surface and said tape-engaging plate, and means for moving said slide longitudinally of said tapesupporting surface and relative to said bridge-piece to maintain said tape-engaging plate in any one of a plurality of adjusted positions normal to said tape-supporting surface.

References Cited in the file of this patent UNITED STATES PATENTS 1,317,865 De Voe Oct. 7, 1919 1,463,262 Gray July 31, 1923 2,149,755 Ackerman Mar. 7, 1939 2,278,042 Sailer Mar. 31, 1942 FOREIGN PATENTS 12,125 Great Britain May 24, 1913 

